-- in source files, and allow tagging of those things with locations
module SrcLoc (
-- * SrcLoc
- SrcLoc, -- Abstract
+ RealSrcLoc, -- Abstract
+ SrcLoc(..),
-- ** Constructing SrcLoc
- mkSrcLoc, mkGeneralSrcLoc,
+ mkSrcLoc, mkRealSrcLoc, mkGeneralSrcLoc,
noSrcLoc, -- "I'm sorry, I haven't a clue"
generatedSrcLoc, -- Code generated within the compiler
-- ** Misc. operations on SrcLoc
pprDefnLoc,
-
- -- ** Predicates on SrcLoc
- isGoodSrcLoc,
-- * SrcSpan
- SrcSpan, -- Abstract
+ RealSrcSpan, -- Abstract
+ SrcSpan(..),
-- ** Constructing SrcSpan
- mkGeneralSrcSpan, mkSrcSpan,
+ mkGeneralSrcSpan, mkSrcSpan, mkRealSrcSpan,
noSrcSpan,
wiredInSrcSpan, -- Something wired into the compiler
- srcLocSpan,
+ srcLocSpan, realSrcLocSpan,
combineSrcSpans,
-- ** Deconstructing SrcSpan
srcSpanStart, srcSpanEnd,
+ realSrcSpanStart, realSrcSpanEnd,
srcSpanFileName_maybe,
-- ** Unsafely deconstructing SrcSpan
isGoodSrcSpan, isOneLineSpan,
-- * Located
- Located(..),
+ Located,
+ RealLocated,
+ GenLocated(..),
-- ** Constructing Located
noLoc,
spans, isSubspanOf
) where
+#include "Typeable.h"
+
import Util
import Outputable
import FastString
+
+import Data.Bits
+import Data.Data
\end{code}
%************************************************************************
this is the obvious stuff:
\begin{code}
-- | Represents a single point within a file
-data SrcLoc
+data RealSrcLoc
= SrcLoc FastString -- A precise location (file name)
{-# UNPACK #-} !Int -- line number, begins at 1
- {-# UNPACK #-} !Int -- column number, begins at 0
- -- Don't ask me why lines start at 1 and columns start at
- -- zero. That's just the way it is, so there. --SDM
+ {-# UNPACK #-} !Int -- column number, begins at 1
+data SrcLoc
+ = RealSrcLoc {-# UNPACK #-}!RealSrcLoc
| UnhelpfulLoc FastString -- Just a general indication
\end{code}
\begin{code}
mkSrcLoc :: FastString -> Int -> Int -> SrcLoc
-mkSrcLoc x line col = SrcLoc x line col
+mkSrcLoc x line col = RealSrcLoc (mkRealSrcLoc x line col)
+
+mkRealSrcLoc :: FastString -> Int -> Int -> RealSrcLoc
+mkRealSrcLoc x line col = SrcLoc x line col
-- | Built-in "bad" 'SrcLoc' values for particular locations
noSrcLoc, generatedSrcLoc, interactiveSrcLoc :: SrcLoc
mkGeneralSrcLoc :: FastString -> SrcLoc
mkGeneralSrcLoc = UnhelpfulLoc
--- | "Good" 'SrcLoc's have precise information about their location
-isGoodSrcLoc :: SrcLoc -> Bool
-isGoodSrcLoc (SrcLoc _ _ _) = True
-isGoodSrcLoc _other = False
-
--- | Gives the filename of the 'SrcLoc' if it is available, otherwise returns a dummy value
-srcLocFile :: SrcLoc -> FastString
+-- | Gives the filename of the 'RealSrcLoc'
+srcLocFile :: RealSrcLoc -> FastString
srcLocFile (SrcLoc fname _ _) = fname
-srcLocFile _other = (fsLit "<unknown file")
-- | Raises an error when used on a "bad" 'SrcLoc'
-srcLocLine :: SrcLoc -> Int
+srcLocLine :: RealSrcLoc -> Int
srcLocLine (SrcLoc _ l _) = l
-srcLocLine _other = panic "srcLocLine: unknown line"
-- | Raises an error when used on a "bad" 'SrcLoc'
-srcLocCol :: SrcLoc -> Int
+srcLocCol :: RealSrcLoc -> Int
srcLocCol (SrcLoc _ _ c) = c
-srcLocCol _other = panic "srcLocCol: unknown col"
--- | Move the 'SrcLoc' down by one line if the character is a newline
--- and across by one character in any other case
-advanceSrcLoc :: SrcLoc -> Char -> SrcLoc
-advanceSrcLoc (SrcLoc f l _) '\n' = SrcLoc f (l + 1) 0
+-- | Move the 'SrcLoc' down by one line if the character is a newline,
+-- to the next 8-char tabstop if it is a tab, and across by one
+-- character in any other case
+advanceSrcLoc :: RealSrcLoc -> Char -> RealSrcLoc
+advanceSrcLoc (SrcLoc f l _) '\n' = SrcLoc f (l + 1) 1
+advanceSrcLoc (SrcLoc f l c) '\t' = SrcLoc f l (((((c - 1) `shiftR` 3) + 1)
+ `shiftL` 3) + 1)
advanceSrcLoc (SrcLoc f l c) _ = SrcLoc f l (c + 1)
-advanceSrcLoc loc _ = loc -- Better than nothing
\end{code}
%************************************************************************
-- SrcLoc is an instance of Ord so that we can sort error messages easily
instance Eq SrcLoc where
loc1 == loc2 = case loc1 `cmpSrcLoc` loc2 of
- EQ -> True
- _other -> False
+ EQ -> True
+ _other -> False
+
+instance Eq RealSrcLoc where
+ loc1 == loc2 = case loc1 `cmpRealSrcLoc` loc2 of
+ EQ -> True
+ _other -> False
instance Ord SrcLoc where
compare = cmpSrcLoc
-
+
+instance Ord RealSrcLoc where
+ compare = cmpRealSrcLoc
+
cmpSrcLoc :: SrcLoc -> SrcLoc -> Ordering
cmpSrcLoc (UnhelpfulLoc s1) (UnhelpfulLoc s2) = s1 `compare` s2
-cmpSrcLoc (UnhelpfulLoc _) _other = LT
+cmpSrcLoc (UnhelpfulLoc _) (RealSrcLoc _) = GT
+cmpSrcLoc (RealSrcLoc _) (UnhelpfulLoc _) = LT
+cmpSrcLoc (RealSrcLoc l1) (RealSrcLoc l2) = (l1 `compare` l2)
-cmpSrcLoc (SrcLoc s1 l1 c1) (SrcLoc s2 l2 c2)
+cmpRealSrcLoc :: RealSrcLoc -> RealSrcLoc -> Ordering
+cmpRealSrcLoc (SrcLoc s1 l1 c1) (SrcLoc s2 l2 c2)
= (s1 `compare` s2) `thenCmp` (l1 `compare` l2) `thenCmp` (c1 `compare` c2)
-cmpSrcLoc (SrcLoc _ _ _) _other = GT
-instance Outputable SrcLoc where
+instance Outputable RealSrcLoc where
ppr (SrcLoc src_path src_line src_col)
= getPprStyle $ \ sty ->
if userStyle sty || debugStyle sty then
hcat [text "{-# LINE ", int src_line, space,
char '\"', pprFastFilePath src_path, text " #-}"]
+instance Outputable SrcLoc where
+ ppr (RealSrcLoc l) = ppr l
ppr (UnhelpfulLoc s) = ftext s
+
+instance Data RealSrcSpan where
+ -- don't traverse?
+ toConstr _ = abstractConstr "RealSrcSpan"
+ gunfold _ _ = error "gunfold"
+ dataTypeOf _ = mkNoRepType "RealSrcSpan"
+
+instance Data SrcSpan where
+ -- don't traverse?
+ toConstr _ = abstractConstr "SrcSpan"
+ gunfold _ _ = error "gunfold"
+ dataTypeOf _ = mkNoRepType "SrcSpan"
\end{code}
%************************************************************************
span. That is, a span of (1,1)-(1,2) is one character long, and a
span of (1,1)-(1,1) is zero characters long.
-}
-data SrcSpan
+data RealSrcSpan
= SrcSpanOneLine -- a common case: a single line
{ srcSpanFile :: !FastString,
srcSpanLine :: {-# UNPACK #-} !Int,
srcSpanLine :: {-# UNPACK #-} !Int,
srcSpanCol :: {-# UNPACK #-} !Int
}
+#ifdef DEBUG
+ deriving (Eq, Typeable, Show) -- Show is used by Lexer.x, becuase we
+ -- derive Show for Token
+#else
+ deriving (Eq, Typeable)
+#endif
+data SrcSpan =
+ RealSrcSpan !RealSrcSpan
| UnhelpfulSpan !FastString -- Just a general indication
-- also used to indicate an empty span
#ifdef DEBUG
- deriving (Eq, Show) -- Show is used by Lexer.x, becuase we
- -- derive Show for Token
+ deriving (Eq, Typeable, Show) -- Show is used by Lexer.x, becuase we
+ -- derive Show for Token
#else
- deriving Eq
+ deriving (Eq, Typeable)
#endif
-- | Built-in "bad" 'SrcSpan's for common sources of location uncertainty
-- | Create a 'SrcSpan' corresponding to a single point
srcLocSpan :: SrcLoc -> SrcSpan
srcLocSpan (UnhelpfulLoc str) = UnhelpfulSpan str
-srcLocSpan (SrcLoc file line col) = SrcSpanPoint file line col
+srcLocSpan (RealSrcLoc l) = RealSrcSpan (realSrcLocSpan l)
+
+realSrcLocSpan :: RealSrcLoc -> RealSrcSpan
+realSrcLocSpan (SrcLoc file line col) = SrcSpanPoint file line col
-- | Create a 'SrcSpan' between two points in a file
-mkSrcSpan :: SrcLoc -> SrcLoc -> SrcSpan
-mkSrcSpan (UnhelpfulLoc str) _ = UnhelpfulSpan str
-mkSrcSpan _ (UnhelpfulLoc str) = UnhelpfulSpan str
-mkSrcSpan loc1 loc2
+mkRealSrcSpan :: RealSrcLoc -> RealSrcLoc -> RealSrcSpan
+mkRealSrcSpan loc1 loc2
| line1 == line2 = if col1 == col2
then SrcSpanPoint file line1 col1
else SrcSpanOneLine file line1 col1 col2
col2 = srcLocCol loc2
file = srcLocFile loc1
+-- | Create a 'SrcSpan' between two points in a file
+mkSrcSpan :: SrcLoc -> SrcLoc -> SrcSpan
+mkSrcSpan (UnhelpfulLoc str) _ = UnhelpfulSpan str
+mkSrcSpan _ (UnhelpfulLoc str) = UnhelpfulSpan str
+mkSrcSpan (RealSrcLoc loc1) (RealSrcLoc loc2)
+ = RealSrcSpan (mkRealSrcSpan loc1 loc2)
+
-- | Combines two 'SrcSpan' into one that spans at least all the characters
-- within both spans. Assumes the "file" part is the same in both inputs
combineSrcSpans :: SrcSpan -> SrcSpan -> SrcSpan
combineSrcSpans (UnhelpfulSpan _) r = r -- this seems more useful
combineSrcSpans l (UnhelpfulSpan _) = l
-combineSrcSpans start end
- = case line1 `compare` line2 of
- EQ -> case col1 `compare` col2 of
- EQ -> SrcSpanPoint file line1 col1
- LT -> SrcSpanOneLine file line1 col1 col2
- GT -> SrcSpanOneLine file line1 col2 col1
- LT -> SrcSpanMultiLine file line1 col1 line2 col2
- GT -> SrcSpanMultiLine file line2 col2 line1 col1
+combineSrcSpans (RealSrcSpan span1) (RealSrcSpan span2)
+ = RealSrcSpan (combineRealSrcSpans span1 span2)
+
+-- | Combines two 'SrcSpan' into one that spans at least all the characters
+-- within both spans. Assumes the "file" part is the same in both inputs
+combineRealSrcSpans :: RealSrcSpan -> RealSrcSpan -> RealSrcSpan
+combineRealSrcSpans span1 span2
+ = if line_start == line_end
+ then if col_start == col_end
+ then SrcSpanPoint file line_start col_start
+ else SrcSpanOneLine file line_start col_start col_end
+ else SrcSpanMultiLine file line_start col_start line_end col_end
where
- line1 = srcSpanStartLine start
- col1 = srcSpanStartCol start
- line2 = srcSpanEndLine end
- col2 = srcSpanEndCol end
- file = srcSpanFile start
+ (line_start, col_start) = min (srcSpanStartLine span1, srcSpanStartCol span1)
+ (srcSpanStartLine span2, srcSpanStartCol span2)
+ (line_end, col_end) = max (srcSpanEndLine span1, srcSpanEndCol span1)
+ (srcSpanEndLine span2, srcSpanEndCol span2)
+ file = srcSpanFile span1
\end{code}
%************************************************************************
\begin{code}
-- | Test if a 'SrcSpan' is "good", i.e. has precise location information
isGoodSrcSpan :: SrcSpan -> Bool
-isGoodSrcSpan SrcSpanOneLine{} = True
-isGoodSrcSpan SrcSpanMultiLine{} = True
-isGoodSrcSpan SrcSpanPoint{} = True
-isGoodSrcSpan _ = False
+isGoodSrcSpan (RealSrcSpan _) = True
+isGoodSrcSpan (UnhelpfulSpan _) = False
isOneLineSpan :: SrcSpan -> Bool
-- ^ True if the span is known to straddle only one line.
-- For "bad" 'SrcSpan', it returns False
-isOneLineSpan s
- | isGoodSrcSpan s = srcSpanStartLine s == srcSpanEndLine s
- | otherwise = False
+isOneLineSpan (RealSrcSpan s) = srcSpanStartLine s == srcSpanEndLine s
+isOneLineSpan (UnhelpfulSpan _) = False
\end{code}
\begin{code}
--- | Raises an error when used on a "bad" 'SrcSpan'
-srcSpanStartLine :: SrcSpan -> Int
--- | Raises an error when used on a "bad" 'SrcSpan'
-srcSpanEndLine :: SrcSpan -> Int
--- | Raises an error when used on a "bad" 'SrcSpan'
-srcSpanStartCol :: SrcSpan -> Int
--- | Raises an error when used on a "bad" 'SrcSpan'
-srcSpanEndCol :: SrcSpan -> Int
+srcSpanStartLine :: RealSrcSpan -> Int
+srcSpanEndLine :: RealSrcSpan -> Int
+srcSpanStartCol :: RealSrcSpan -> Int
+srcSpanEndCol :: RealSrcSpan -> Int
srcSpanStartLine SrcSpanOneLine{ srcSpanLine=l } = l
srcSpanStartLine SrcSpanMultiLine{ srcSpanSLine=l } = l
srcSpanStartLine SrcSpanPoint{ srcSpanLine=l } = l
-srcSpanStartLine _ = panic "SrcLoc.srcSpanStartLine"
srcSpanEndLine SrcSpanOneLine{ srcSpanLine=l } = l
srcSpanEndLine SrcSpanMultiLine{ srcSpanELine=l } = l
srcSpanEndLine SrcSpanPoint{ srcSpanLine=l } = l
-srcSpanEndLine _ = panic "SrcLoc.srcSpanEndLine"
srcSpanStartCol SrcSpanOneLine{ srcSpanSCol=l } = l
srcSpanStartCol SrcSpanMultiLine{ srcSpanSCol=l } = l
srcSpanStartCol SrcSpanPoint{ srcSpanCol=l } = l
-srcSpanStartCol _ = panic "SrcLoc.srcSpanStartCol"
srcSpanEndCol SrcSpanOneLine{ srcSpanECol=c } = c
srcSpanEndCol SrcSpanMultiLine{ srcSpanECol=c } = c
srcSpanEndCol SrcSpanPoint{ srcSpanCol=c } = c
-srcSpanEndCol _ = panic "SrcLoc.srcSpanEndCol"
\end{code}
-- | Returns the location at the start of the 'SrcSpan' or a "bad" 'SrcSpan' if that is unavailable
srcSpanStart :: SrcSpan -> SrcLoc
+srcSpanStart (UnhelpfulSpan str) = UnhelpfulLoc str
+srcSpanStart (RealSrcSpan s) = RealSrcLoc (realSrcSpanStart s)
+
-- | Returns the location at the end of the 'SrcSpan' or a "bad" 'SrcSpan' if that is unavailable
srcSpanEnd :: SrcSpan -> SrcLoc
+srcSpanEnd (UnhelpfulSpan str) = UnhelpfulLoc str
+srcSpanEnd (RealSrcSpan s) = RealSrcLoc (realSrcSpanEnd s)
-srcSpanStart (UnhelpfulSpan str) = UnhelpfulLoc str
-srcSpanStart s = mkSrcLoc (srcSpanFile s)
- (srcSpanStartLine s)
- (srcSpanStartCol s)
+realSrcSpanStart :: RealSrcSpan -> RealSrcLoc
+realSrcSpanStart s = mkRealSrcLoc (srcSpanFile s)
+ (srcSpanStartLine s)
+ (srcSpanStartCol s)
-srcSpanEnd (UnhelpfulSpan str) = UnhelpfulLoc str
-srcSpanEnd s =
- mkSrcLoc (srcSpanFile s)
- (srcSpanEndLine s)
- (srcSpanEndCol s)
+realSrcSpanEnd :: RealSrcSpan -> RealSrcLoc
+realSrcSpanEnd s = mkRealSrcLoc (srcSpanFile s)
+ (srcSpanEndLine s)
+ (srcSpanEndCol s)
-- | Obtains the filename for a 'SrcSpan' if it is "good"
srcSpanFileName_maybe :: SrcSpan -> Maybe FastString
-srcSpanFileName_maybe (SrcSpanOneLine { srcSpanFile = nm }) = Just nm
-srcSpanFileName_maybe (SrcSpanMultiLine { srcSpanFile = nm }) = Just nm
-srcSpanFileName_maybe (SrcSpanPoint { srcSpanFile = nm}) = Just nm
-srcSpanFileName_maybe _ = Nothing
+srcSpanFileName_maybe (RealSrcSpan s) = Just (srcSpanFile s)
+srcSpanFileName_maybe (UnhelpfulSpan _) = Nothing
\end{code}
(srcSpanEnd a `compare` srcSpanEnd b)
-instance Outputable SrcSpan where
+instance Outputable RealSrcSpan where
ppr span
= getPprStyle $ \ sty ->
if userStyle sty || debugStyle sty then
- pprUserSpan span
+ pprUserRealSpan True span
else
hcat [text "{-# LINE ", int (srcSpanStartLine span), space,
char '\"', pprFastFilePath $ srcSpanFile span, text " #-}"]
-pprUserSpan :: SrcSpan -> SDoc
-pprUserSpan (SrcSpanOneLine src_path line start_col end_col)
- = hcat [ pprFastFilePath src_path, char ':',
- int line,
- char ':', int start_col
- ]
- <> if end_col - start_col <= 1
- then empty
- -- for single-character or point spans, we just output the starting
- -- column number
- else char '-' <> int (end_col-1)
-
-pprUserSpan (SrcSpanMultiLine src_path sline scol eline ecol)
- = hcat [ pprFastFilePath src_path, char ':',
- parens (int sline <> char ',' <> int scol),
- char '-',
- parens (int eline <> char ',' <>
- if ecol == 0 then int ecol else int (ecol-1))
- ]
-
-pprUserSpan (SrcSpanPoint src_path line col)
- = hcat [ pprFastFilePath src_path, char ':',
- int line,
- char ':', int col
+instance Outputable SrcSpan where
+ ppr span
+ = getPprStyle $ \ sty ->
+ if userStyle sty || debugStyle sty then
+ pprUserSpan True span
+ else
+ case span of
+ UnhelpfulSpan _ -> panic "Outputable UnhelpfulSpan"
+ RealSrcSpan s -> ppr s
+
+pprUserSpan :: Bool -> SrcSpan -> SDoc
+pprUserSpan _ (UnhelpfulSpan s) = ftext s
+pprUserSpan show_path (RealSrcSpan s) = pprUserRealSpan show_path s
+
+pprUserRealSpan :: Bool -> RealSrcSpan -> SDoc
+pprUserRealSpan show_path (SrcSpanOneLine src_path line start_col end_col)
+ = hcat [ ppWhen show_path (pprFastFilePath src_path <> colon)
+ , int line, char ':', int start_col
+ , ppUnless (end_col - start_col <= 1)
+ (char '-' <> int (end_col-1))
+ -- For single-character or point spans, we just
+ -- output the starting column number
+ ]
+
+
+pprUserRealSpan show_path (SrcSpanMultiLine src_path sline scol eline ecol)
+ = hcat [ ppWhen show_path (pprFastFilePath src_path <> colon)
+ , parens (int sline <> char ',' <> int scol)
+ , char '-'
+ , parens (int eline <> char ',' <>
+ if ecol == 0 then int ecol else int (ecol-1))
]
-pprUserSpan (UnhelpfulSpan s) = ftext s
+pprUserRealSpan show_path (SrcSpanPoint src_path line col)
+ = hcat [ ppWhen show_path $ (pprFastFilePath src_path <> colon)
+ , int line, char ':', int col ]
-pprDefnLoc :: SrcSpan -> SDoc
+pprDefnLoc :: RealSrcSpan -> SDoc
-- ^ Pretty prints information about the 'SrcSpan' in the style "defined at ..."
-pprDefnLoc loc
- | isGoodSrcSpan loc = ptext (sLit "Defined at") <+> ppr loc
- | otherwise = ppr loc
+pprDefnLoc loc = ptext (sLit "Defined at") <+> ppr loc
\end{code}
%************************************************************************
\begin{code}
-- | We attach SrcSpans to lots of things, so let's have a datatype for it.
-data Located e = L SrcSpan e
+data GenLocated l e = L l e
+ deriving (Eq, Ord, Typeable, Data)
-unLoc :: Located e -> e
+type Located e = GenLocated SrcSpan e
+type RealLocated e = GenLocated RealSrcSpan e
+
+unLoc :: GenLocated l e -> e
unLoc (L _ e) = e
-getLoc :: Located e -> SrcSpan
+getLoc :: GenLocated l e -> l
getLoc (L l _) = l
noLoc :: e -> Located e
cmpLocated :: Ord a => Located a -> Located a -> Ordering
cmpLocated a b = unLoc a `compare` unLoc b
-instance Functor Located where
+instance Functor (GenLocated l) where
fmap f (L l e) = L l (f e)
-instance Outputable e => Outputable (Located e) where
- ppr (L _ e) = ppr e
- -- do we want to dump the span in debugSty mode?
+instance (Outputable l, Outputable e) => Outputable (GenLocated l e) where
+ ppr (L l e) = -- TODO: We can't do this since Located was refactored into
+ -- GenLocated:
+ -- Print spans without the file name etc
+ -- ifPprDebug (braces (pprUserSpan False l))
+ ifPprDebug (braces (ppr l))
+ $$ ppr e
\end{code}
%************************************************************************
`thenCmp`
(srcSpanEnd b `compare` srcSpanEnd a)
-
-- | Determines whether a span encloses a given line and column index
spans :: SrcSpan -> (Int, Int) -> Bool
-spans span (l,c) = srcSpanStart span <= loc && loc <= srcSpanEnd span
- where loc = mkSrcLoc (srcSpanFile span) l c
+spans (UnhelpfulSpan _) _ = panic "spans UnhelpfulSpan"
+spans (RealSrcSpan span) (l,c) = realSrcSpanStart span <= loc && loc <= realSrcSpanEnd span
+ where loc = mkRealSrcLoc (srcSpanFile span) l c
-- | Determines whether a span is enclosed by another one
isSubspanOf :: SrcSpan -- ^ The span that may be enclosed by the other